Table 1.
Closed ER: DNA-replication sites entirely surrounded by membranes of the rough ER.
Open ER: DNA-replication sites in which the surrounding ER is not (yet) surrounding the DNA-site completely.
For each DNA-replication site the amount of ribosomes on the ER facing the cytoplasm and facing the interior of the site were counted and the percentage of ribosomes on the outside (facing the cytoplasm) determined. The values represent the average percentage and the standard deviation. N=16.